yz400 Valve Adjustment

24 replies to this topic
  • rickybobby2189

Posted May 12, 2011 - 10:00 AM


Ok everytime I think I have got what info I need something else pops up....Will I need a new set of valve guides or are they re-usable?? THANKS grayracer

  • grayracer513

Posted May 12, 2011 - 10:22 AM


The valve guides almost never need replacing on a YZF. If you do replace them, it is imperative that you have a machinist refinish the seats and install new valves.

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  • rickybobby2189

Posted May 18, 2011 - 04:09 PM


Well got what I needed to do the job..I thought. The compressor I got had a collar that was way to large to fit in my head. I am assuming I will have to buy one because I cant figure any other way out...Anyone know of anything else I can use to get by?

  • slyfox83c

Posted May 18, 2011 - 05:55 PM


I just adjusted the valves on my 99 yz400 today and yes you are going to need different thickness shims for all your valves. The buckes are no big deal just use a teliscoping magnet to pull them out. Most of the shims will come out with the buckets. You just need a real good set of feeler guages.
As far as the spring compressor yes you will need one. You can use a carberator screwdriver with the built in magnet. you will need it to remove and install the retaining clips for your valves.
I am still fighting my bike's running issues. hard to start and wont idol. I just ordered a jet kit from JD and i hope it fixes it. Every thing else is checking out.
Good luck with your race.

  • rickybobby2189

Posted May 18, 2011 - 05:58 PM


i just now figured a way without the spring compressor i used a monkey wrench and a roach clip as the stoners call them lol...i got them out like that and put one set back in just for a test before i put the seals in...iam glad i figured that out

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